16 Transa<tions. — Miscellatieotis. 



Ere many centuries have passed away it may be that the remnants 

 of the ancient shallow sea, marked on the map of Australia as Lake 

 Torrens, Lake Eyre, Lake Gardiner, etc. — which, with their margms of 

 black, fetid mud, supporting scattered tufts of salsolaceous jjlants, resemble 

 the salt lakes of Siberia and Patagonia, regions which were also in recent 

 times raised from beneath the- sea — will be silted up and then drained, the 

 climate will be still drier and subject to greater extremes of diurnal tempera- 

 ture, remarkable as there are now in the interior as far as 18° S. latitude. 

 The Barcoo or Thomson river will cut a canal-like channel through the 

 sandhills to the head of Spencer's Gulf as the DarHug has done further - 

 east. The surplus waters, after the periodical deluges of rain in the tropical 

 country from which thej flow, spread out over vast areas of the central 

 depression, and already during very high floods find an outlet from Lake 

 Torrens at Port Augusta, where the land is estimated to have risen seven 

 feet since the first survey of that harbour was made. 



The change in this region from a mediterranean sea to arid plains 

 (where, notwithstanding the 10° difference iu temperature between 

 places in the southern and those in corresponding latitudes in the northern 

 hemisphere generally, the heat from various causes is much greater than 

 in the African deserts in similar parallels) must have exercised a most 

 potent influence upon the climate of New Zealand and the adjacent oceanic 

 regions, as it does to a considerable extent to-day, when alternate cycles 

 of wet and dry seasons prevail over these great levels, now torrid deserts, 

 and at other times in great part covered with water ; an influence not very 

 greatly inferior to that which the drying of the Sahara must have produced 

 upon the climate of Europe, and the dimensions of the Alpuie glaciers. 

 When that desert region which now, " like an immense fm-nace," distributes 

 its heat around over distant lands, was covered by the sea, and a large 

 portion of Europe was likewise submerged, over which came berg-laden 

 arctic currents, it may well be conceived that the higher elevation of 

 its central chain of mountains, estimated by Professor Ramsay to have been 

 from two to three thousand feet at the time their glaciers attained such 

 colossal demeusious, was sufficient to produce all the phenomena attributed 

 to a general age of ice, which may come to be i^roved to a great extent, 

 should the project of letting the sea into the great depression of the African 

 Desert be carried out. 



There may be grounds for supposing an ice- sheet of vast extent 

 to have covered gi-eat portion of Northern Europe, Asia, and America, 

 at or about the same era, but evidence of its having been universal 

 is wanting even m the northern hemisphere, and any evidence of an 

 approaching similar state of things in the southern is sought for iu vain. 



